Motorola WIRELESS TELEPHONE - Manual (Page 35)

18 add’l safety info
73
of the nerve sheath). No statistically significant association
was found between mobile phone use and acoustic
neuroma. There was also no association between mobile
phone use and gliomas when all types of types of gliomas
were considered together. It should be noted that the
average length of mobile phone exposure in this study was
less than three years.
When 20 types of glioma were considered separately,
however, an association was found between mobile phone
use and one rare type of glioma, neuroepithelliomatous
tumors. It is possible with multiple comparisons of the same
sample that this association occurred by chance. Moreover,
the risk did not increase with how often the mobile phone
was used, or the length of the calls. In fact, the risk actually
decreased with cumulative hours of mobile phone use. Most
cancer causing agents increase risk with increased exposure.
An ongoing study of brain cancers by the National Cancer
Institute is expected to bear on the accuracy and repeatability
of these results.
1
b Researchers conducted a large battery of laboratory tests to
assess the effects of exposure to mobile phone RF on genetic
material. These included tests for several kinds of
abnormalities, including mutations, chromosomal
aberrations, DNA strand breaks, and structural changes in the
genetic material of blood cells called lymphocytes. None of
the tests showed any effect of the RF except for the
micronucleus assay, which detects structural effects on the
genetic material. The cells in this assay showed changes after
exposure to simulated cell phone radiation, but only after 24
hours of exposure. It is possible that exposing the test cells to
radiation for this long resulted in heating. Since this assay is
known to be sensitive to heating, heat alone could have
caused the abnormalities to occur. The data already in the
literature on the response of the micronucleus assay to RF are
conflicting. Thus, follow-up research is necessary.
2
FDA is currently working with government, industry, and
academic groups to ensure the proper follow-up to these
industry-funded research findings. Collaboration with the
Cellular Telecommunications Industry Association (CTIA) in
18 add’l safety info
74
particular is expected to lead to FDA providing research
recommendations and scientific oversight of new CTIA-
funded research based on such recommendations.
Two other studies of interest have been reported recently in the
literature:
a Two groups of 18 people were exposed to simulated mobile
phone signals under laboratory conditions while they
performed cognitive function tests. There were no changes in
the subjects' ability to recall words, numbers, or pictures, or
in their spatial memory, but they were able to make choices
more quickly in one visual test when they were exposed to
simulated mobile phone signals. This was the only change
noted among more than 20 variables compared.
3
b In a study of 209 brain tumor cases and 425 matched
controls, there was no increased risk of brain tumors
associated with mobile phone use. When tumors did exist in
certain locations, however, they were more likely to be on the
side of the head where the mobile phone was used.
Because this occurred in only a small number of cases, the
increased likelihood was too small to be statistically
significant.
4
In summary, we do not have enough information at this point to
assure the public that there are, or are not, any low incident
health problems associated with use of mobile phones. FDA
continues to work with all parties, including other federal
agencies and industry, to assure that research is undertaken to
provide the necessary answers to the outstanding questions
about the safety of mobile phones.
What is known about cases of human cancer
that have been reported in users of hand-held
mobile phones?
Some people who have used mobile phones have been
diagnosed with brain cancer. But it is important to understand
that this type of cancer also occurs among people who have not
used mobile phones. In fact, brain cancer occurs in the U.S.
population at a rate of about 6 new cases per 100,000 people
each year. At that rate, assuming 80 million users of mobile
phones (a number increasing at a rate of about 1 million per